UBEPOL-BR

High CIS Polybutadiene

Product Description

High CIS Polybutadiene for High Impact Polystyrene (HIPS)

UBEPOL-BR is the brand name of High CIS Polybutadiene produced by using a cobalt catalyst system.

UBEPOL-BR is the brand name of High CIS Polybutadiene produced by using a cobalt catalyst system.

UBE process is characterized by its versatility in producing polybutadiene with different molecular weight distribution and linearity of molecular chain.

There are 6 grades for HIPS: UBEPOL-BR15HB, UBEPOL-BR15H, UBEPOL-BR15HL, UBEPOL-BR13HB, UBEPOL-BR34HL, and UBEPOL-BR22H.

UBEPOL-BR15HB, UBEPOL-BR15H, and UBEPOL-BR15HL are different with respect to solution viscosity, corresponding to the difference in the degree of branching.

UBEPOL-BR13 HB is characterized by the lowest solution viscosity of the 6 grades.

UBEPOL-BR34HL is designed to have lower molecular weight and higher linearity than UBEPOL-BR15HB.

UBEPOL-BR22H is designed to have broad molecular weight distribution.

Properties of UBEPOL- BR for HIPS

(The data of other companys' BR are also listed in comparison with UBEPOL-BR)

Table 1 Typical Properties of UBEPOL-BR
  UBEPOL- BR15HB UBEPOL- BR15H UBEPOL- BR15HL UBEPOL- BR13HB
Money Viscosity (ML1+4,100°C) 40 43 43 30
Volatile Matter (wt.%) 0.3 0.3 0.3 0.3
Ash Content (wt.%) 0.05 0.05 0.05 0.05
 
Micro Structure
(wt. %)
Cis 97 98 98 96
Trans 2 1 1 2
Vinyl 1 1 1 2
Molecular Weight & Molecular Weight Distribution Mw (x 104) 56 61 57 49
Mn (x 104) 17 21 23 13
Mw / Mn 3.3 2.9 2.5 3.8
Lineality of Molecular Chain less medium more less
5wt.% Solution in Styrene Solution Viscosity (cps) 60 92 135 41
Syrene Insolubles (wt. %) 0.005 0.005 0.005 0.005
APHA Color 10 10 10 10
Remarks Branching Type Equivalent to A Standard Type Linear Type Good Gloss
  UBEPOL- BR22H UBEPOL- BR34HL A
(High-Cis)
B
(Low-Cis)
C
(Low-Cis)
Money Viscosity (ML1+4,100°C) 41 34 44 34 52
Volatile Matter (wt.%) 0.3 0.3 -- -- --
Ash Content (wt.%) 0.05 0.05 0.08 0.02 0.02
 
Micro Structure
(wt. %)
Cis 98 98 98 35 35
Trans 1 1 1 55 55
Vinyl 1 1 1 10 10
Molecular Weight & Molecular Weight Distribution Mw (x 104) 70 51 58 37 42.2
Mw (x 104) 15 22 18 15 17.4
Mw / Mn 4.7 2.3 3.2 2.5 2.4
Lineality of Molecular Chain medium more -- -- --
5wt.% Solution in Styrene Solution Viscosity (cps) 202 91 64 87 166
Syrene Insolubles (wt. %) 0.005 0.005 0.015 0.003 0.003
APHA Color 10 10 15 10 10
Remarks Superior Impact Strength Good balance between Gross and Impact Resistance      

Solution Viscosity and Rubber Content

The correlation between rubber content and solution viscosity is given in Fig. 1.

Fig. 1 Rubber Cont. in Styrene vs. Solution Viscosity



Cold Flow
Property of cold flow of UBEPOL-BR is shown in Fig. 2.

Test Method
Fig. 2 Cold Flow of BR



Storage Stability
The change of physical properties of UBEPOL-BR15HB stored for a long time in shown on Table 2.

Table 2
The Change of Physical Properties of UBEPOL-BR15HB Stored for a Long Time
Properties Storage Time (day)
0 86 184 340 380
Mooney Viscosity (ML1+4, 100°C) 41 41 41 40 41
5wt.% Solutionin Styrene Solution Viscosity at 25°C (cps) 61 60 62 58 59
Styrene Insolubles (wt.%) 0.005 0.006 0.008 0.008 0.007
APHA Color 10 10 10 10 10



Application for HIPS

We conducted the test of HIPS which is produced using the raw polymer (polybutadiene) as shown on Table 1 under the following polymerization conditions.

Polymerization Condition
Pre-Polymerization (at Bulk) Characteristics
Rubber Cement 7 wt. %
Temperature 135°C
Reactor 1 lit. separable flask
Impeller Anchor type
Condition (1)
Chaintransfer
n-DM=0.03 wt. %
Condition (2)
Chaintransfer
n-DM=0.03 wt. %
Catalyst PH-3M=0.03 wt. %
Polymerization (at Suspension)
Reactor 1.5 lit. autoclave
Catalyst BPO/DCP=0.2/0.2 wt. %
Stabilizer for Suspension PVA
Temp. x Temp. 100°C x 2 hrs 125°C x 3 hrs 140°C x 2hrs
(Note)
n-DM N-Dodecyl mercaptane
PH-3M 1,1'-Di-(t-butylperoxy)-3,3,5-trimethylcyclohexane
BPO Benzoyl peroxide
DCP Dicumyl peroxide
PVA Polyvinyl alcohol

Test Method
Toluene Insolubles: Weight % Toulene Insolubles in HIPS
Swelling Index: (Wet Weight/Dry Weight) of Toulene Insolubles
MEK/Acetone Insolubles: Weight % of MEK/Acetone Insolubles in HIPS
(MEK / Acetone = 50/50)
Melt Flow Index: ASTM D1238, 200°C, 5kg
Tensile Strength: ASTM D638
Elongation: ASTM D638
Izod Impact Strength: ASTM D256, Notched, Thickness of Specimen, 3.16 mm
Gloss: JIS Z8741 Incidence Angle 60°
Vicat Softening Point: ASTM D1525
Rubber Particle Size;  
Equipment: Caulter Counter, TA II Model
Dispersion Medium: Dimetlyl Formamide
Electrolyte: Ammonium Thiocyanate
Aperture Tube: 30µ

Characteristics of HIPS in UBEPOL-BR15HB, UBEPOL-BR15H, and UBEPOL-BR15HL

BR15HB is characterized by the highest branching of these 3 grades and is adapted by many PS manufacturers.

BR15HL is a linear type of polymer with high-solution viscosity.

When enlarging the dispersed rubber particle size in HIPS, this polymer can be useful for PS manufacturers.

The characteristics of BR15H lie in between those of BR15HB and BR15HL.

Physical Properties of HIPS

Polymerization was performed by (1) and (2) of pre-polymerization condition, and the physical properties of the obtained HIPS are shown on Table 3.

Table 3. Physical Properties of HIPS
Pre- polymerization Condition Grade Swelling Index MEK/ Acetone Insolubles (wt.%) Rubber Particle Size (µ) Tensile Strength (MPa)
at yield at break
(1) n-DM = 0.03wt.%

UBEPOL-BR15HB 10.9 23.0 2.1 30 29
UBEPOL-BR15H 10.7 23.3 2.5 29 29
UBEPOL-BR15HL 10.6 23.5 2.7 29 30
A (High-Cis) 10.8 22.8 2.2 30 29
B (Low-Cis) 10.0 24.7 1.8 31 30
C (Low-Cis) 9.9 26.2 2.2 32 31

(2) n-DM =0.03wt.%PH-3H=0.03wt.%

UBEPOL-BR15HB 13.3 23.4 0.9 34 30
UBEPOL-BR15H 12.9 23.5 1.0 33 30
UBEPOL-BR15HL 12.6 24.1 1.0 33 29
A (High-Cis) 13.2 23.0 0.9 34 30
B (Low-Cis) 12.1 25.3 0.8 35 32
C (Low-Cis) 11.9 26.4 0.9 36 33

Pre- polymerization Condition
Grade
Elongation(%) Izod Impact Strength (J/m) Gloss Vicat Softening Point (°C) Melt Flow Index
(g/10 min.)
(1) n-DM =0.03wt.%

UBEPOL-BR15HB 22 76 59 101 3.6
UBEPOL-BR15H 23 75 56 101 3.5
UBEPOL-BR15HL 25 75 51 101 3.6
A (High-Cis) 22 75 59 101 3.5
B (Low-Cis) 20 66 63 101 3.5
C (Low-Cis) 20 64 58 101 3.5

(2) n-DM =0.03wt.%PH-3H=0.03wt.%

UBEPOL-BR15HB 7 59 78 101 2.8
UBEPOL-BR15H 8 70 80 101 2.7
UBEPOL-BR15HL 8 74 83 101 2.7
A (High-Cis) 7 58 79 101 2.8
B (Low-Cis) 6 49 85 101 2.8
C (Low-Cis) 6 51 83 101 2.8

Low temperature Property of HIPS

Dependence in Fig. 3. Low temperature property of HIPS modified by high cis BR is better than that modified by low cis BR.

Fig. 3 Temperature vs. Izod Impact Strength.
Note: Specimens were kept at test temperature for 5 hrs.

Dissolving Time
UBEPOL-BR13HB has such characteristics as low solution viscosity and short dissolution time in styrene monomer. Fig. 4 shows the transient behavior of UBEPOL-BR13HB form the time when a certain amount of rubber is put into styrene monomer and is stirred until its solution viscosity increases and becomes constant.

Fig. 4-1 Fig. 4-2
Dissolving Time of BR in Styrene Dissolving Time of BR in Styrene

Change of Motor Current During Pre-polymerization
The correlation between conversion ratio and motor current in agitator is given in Fig.5. As UBEPOL-BR13HB is of low molecular weight and a branching type, its viscosity of polymer cement is low up to 6-7% of conversion ratio where a phase inversion takes place, which makes it possible to control to make rubber particles size smaller so that a type oh high gloss HIPS can be obtained. In the case of UBEPOL-BR13HB, stirring power consumption is less for polymerization of HIPS.

Fig. 5
Conversion vs. Motor Current

Physical Properties of HIPS
Polymerization was performed by (1) and (2) of pre-polymerization condition, and the physical properties of the obtained HIPS are shown on Table 4.

Table 4. Physical Properties of HIPS
Pre- polymerization Condition Grade Swelling Index MEK/ Acetone Insolubles (wt.%) Rubber Particle Size (µ) Tensile Strength (MPa)
at yield at break
(1)
n-DM=0.03wt. %
UBEPOL-BR13HB 11.2 22.1 1.6 31 30
UBEPOL-BR15HB 10.9 23.0 2.1 30 29

(2)
n-DM=0.03wt. %
PH-3H=0.03wt.%

UBEPOL-BR13HB

13.7

21.9 0.8 35 31
UBEPOL-BR15HB 13.3 23.4 0.9 34 30

Pre- polymerization Condition Grade Elongation(%) Izod Impact Strength (J/m) Gloss Vicat Softening Point (°C) Melt Flow Index (g/10 min.)
(1)
n-DM=0.03wt. %
UBEPOL-BR13HB

20

72 68 101 3.6
UBEPOL-BR15HB 22 76 59 101 3.6

(2)
n-DM=0.03wt. %
PH-3H=0.03wt.%

UBEPOL-BR13HB

7

53 82 101 2.8
UBEPOL-BR15HB 7 59 78 101 2.8

Characteristics of HIPS in BR13HB

BR13HB is characterized by its low solution viscosity compared with conventional grades.

Short dissolution time in styrene monomer

Small power consumption necessary for agitation for polymerization in HIPS manufacturing process

High rubber content, because of low solution viscosity, produce HIPS of a higher impact strength

It is easy to make small rubber particles in HIPS

Characteristics of HIPS in BR22H

BR22H is characterized by its broad molecular weight distribution, called a "binary polymer".

The properties of HIPS modified by BR22H are extremely good, and better than as performed by (1) and (2) of pre-polymerization condition.

Molecular Weight Distribution

Molecular weight distribution of UBEPOL-BR22H is shown in Fig 6 in comparison with UBEPOL-BR15HB and B (Low cis).

Fig. 6
Molecular Weight Distribution by Gel Permiation Chromatogram.

Physical Properties of HIPS
Polymerization was performed by (1) and (2) of pre-polymerization condition, and the physical properties of the obtained HIPS are shown on Table 5.

Table 5. Physical Properties of HIPS
Pre- polymerization Condition Grade Swelling Index MEK/ Acetone Insolubles (wt.%) Rubber Particle Size (µ) Tensile Strength (MPa)
at yield at break
(1)
n-DM=0.03wt. %
UBEPOL-BR22H 11.3 23.1 2.6 27 28
UBEPOL-BR15HB 10.9 23.0 2.1 30 29
B (Low-Cis) 10.0 24.7 1.8 31 30

(2)
n-DM=0.03wt. %
PH-3H=0.03wt.%

UBEPOL-BR22H 13.5 23.6 1.0 33 29
UBEPOL-BR15HB 13.3 23.4 0.9 34 30
B (Low-Cis) 12.1 25.3 0.8 35 32

Pre- polymerization Condition Grade Elongation(%) Izod Impact Strength (J/m) Gloss Vicat Softening Point (°C) Melt Flow Index (g/10 min.)
(1)
n-DM=0.03wt. %
UBEPOL-BR22H 30 79 54 101 3.5
UBEPOL-BR15HB 22 76 59 101 3.6
B (Low-Cis) 20 66 63 101 3.5

(2)
n-DM=0.03wt. %
PH-3H=0.03wt.%

UBEPOL-BR22H 15 78 80 101 2.8
UBEPOL-BR15HB 7 59 78 101 2.8
B (Low-Cis) 6 49 85 101 2.8

Physical Properties of MIPS (Medium Impact Polystrene)
Polymerization was performed in different stirring rates under pre-polymerization condition (1)(2.5 wt. % rubber content) and the characteristics of the obtained MIPS are shown on Table 6. The correlation between Izod impact strength and rubber particle size is shown in Fig. 7 and correlation between Elongation and Rubber particle size is shown in Fig. 8.

Table 6. Physical Properties of MIPS
Grade Stirring Rate (rpm) Swelling Index MEK/ Acetone Insolubles (wt.%) Rubber Particle Size (µ) Tensile Strength (MPa)
at yield at break
UBEPOL-BR22H 600 12.7 7.3 1.4 41 39
500 12.8 7.8 1.6 38 37
400 13.0 8.2 2.1 36 36
300 13.3 8.8 2.8 36 36
UBEPOL-BR15HB 500 12.9 7.3 1.3 -- 41
400 12.7 7.8 1.5 -- 39
300 12.7 7.9 2.0 40 39
200 13.0 8.6 2.7 39 38

Grade Elongation(%) Izod Impact Strength (J/m) Gloss Vicat Softening Point (°C) Melt Flow Index(g/10 min.)
UBEPOL-BR22H 5 29 96 101 8.3
5 33 94 101 8.2
8 38 92 101 8.0
10 42 87 101 8.1
UBEPOL-BR15HB 3 22 97 101 8.1
4 28 94 101 8.3
6 33 92 101 8.3
6 36 80 101 8.0

Fig. 7 Fig. 8
Rubber Particle Size vs. Izod Impact Strength Rubber Particle Size vs. Elongation

Characteristics of HIPS in BR34HL
BR34HL is characterized by its lower molecular weight and higher linear molecular chain compared with BR15HB. The properties of HIPS modified by BR34HL are significantly better than the other grades with respect to the balance between gloss and impact resistance

Physical Properties of HIPS
Polymerization was performed in different stirring rates under pre-polymerization condition (2) and the characteristics of the obtained HIPS are shown on Table 7. The correlation between glass and rubber particle size is shown in Fig. 9 and the correlation between gloss and Izod impact strength is shown in Fig. 10

Table 7. Physical Properties of HIPS
Grade Stirring Index Swelling Index MEK/ Acetone Insolubles (wt.%) Rubber Particle Size (µ) Tensile Strength (MPa)
at yield at break
UBEPOL-BR34HL 500 12.7 24.0 0.94 34 30
400 11.9 25.2 1.23 31 30
UBEPOL-BR15HB 500 13.3 23.4 0.89 34 30
400 12.5 24.4 1.18 33 30
B (Low-cis) 500 12.1 25.3 0.82 35 32

Grade Elongation(%) Izod Impact Strength (J/m) Gloss Vicat Softening Point (°C) Melt Flow Index(g/10 min.)
UBEPOL-BR34HL 9 69 86 101 2.8
43 79 80 101 2.7
UBEPOL-BR15HB 7 59 78 101 2.8
34 74 74 101 2.6
B (Low-cis) 6 49 85 101 2.8

Fig. 9 Fig. 10
Stirring Rate vs. Gloss Izod Impact Strength vs. Gloss